Monster who can't save you, but will bury you
At their northeastern edge, the sands of the Night Country and surrounding deserts gives way to the weird and broken landscape of the Glass Wastes, still-hot battlefield of the Age of Mages' most destructive violence.
Beneath the Night Country, beneath Subcthonia's tunnels, lies a huge and brackish, sunless lake, peopled with carcharhinid merfolk.
This Dread Lord lets any foolish adventurer who challenges their tower go free afterwards, but insists they fill out a comment card first.
Since this mage learned to cast Reverse Gravity, they've been using it for every situation.